1. Field of the Invention
The present invention relates to a method of producing a cover layer of amorphous carbon, which contains hydrogen and/or fluorine as an additional element, on a substrate. The invention also relates to a cover layer produced according to such a method.
2. Discussion of the Background
Cover layers of hydrogenated amorphous carbon (a--C:H) are used because of their great hardness. It is known to produce such cover layers by glow discharge at high frequencies from an acetylene gas atmosphere in conjunction with argon. Due to the low deposition rate, the production of cover layers according to this method is complicated, time consuming and expensive.
It has also been attempted to produce layers of amorphous carbon by means of direct current cathode sputtering using graphite as the target. The latter method is performed with aperture (diaphragm) systems (Journal of Non-Crystalline Solids 35 & 36 (1980), North Holland Publishing Company, pages 543-548).